/*
 * Copyright (c) 2011-2012 Alexander Dubu
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * o  Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * o  Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * o  Neither the name Axil nor the names of its contributors may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

package axil.definition;

import axil.api.AxilObject;
import axil.api.AxilType;
import axil.engine.Repository;
import axil.framework.validation.Validated;
import axil.framework.validation.ValidationContext;
import axil.framework.xml.InputXML;

import static axil.framework.Functions.*;


/**
 * An XML-based representation of the result of a function.
 */
public class Result implements Validated {
	private String type;
	private String text;

	private transient AxilObject value;


	public Result(InputXML xml) {
		type = xml.text("type");
		text = xml.content();
	}


	/**
	 * Return a string by which this object's value can be identified. The
	 * string returned cannot be null, but may be empty.
	 */
	public String identity() {
		return require(text);
	}


	public String type() {
		return type;
	}
	public String text() {
		return text;
	}


	/**
	 * Get the resulting value as an Axil object. Note that this cannot be
	 * invoked when the output type is something like "any" or "output".
	 */
	public AxilObject value() {
		if (value == null) {
			AxilType t = Repository.instance().type(type);
			if (t == null) {
				throw abort("There is no such type.", nv("type", type));
			}
			value = t.parse(text);
		}
		return value;
	}


	/**
	 * Validate this object in the given context. Any problems detected with the
	 * correctness or completeness of this object are placed into the context.
	 * This method descends into its owned members, validating them as well.
	 */
	public void validate(ValidationContext context) {
		context.required("type", type);
	}
}
